Tagged Questions
2
votes
3answers
99 views
How to test if geometry is inside another?
I need to tell whether geometries from a shapefile are inside other geometries or not.
For example, I want to test if there are trees (represented as points in trees.shp) inside the urban areas ...
0
votes
0answers
30 views
Slicing / Cutting a Polygon / Polygon List based on another geometry
I currently use GeoDjango (GEOS, GDAL, PROJ4), I have rather medium set of polygon data (buildings).
To streamline them to a client efficiently (client has a limited viewport) I only want to send the ...
1
vote
1answer
54 views
How to use QgsOverlayAnalyzer class in pyQGIS?
I am very new to Python scripting in QuantumGIS, so bear with me please.
I am trying to use the QgsOverlayAnalyzer class in QuantumGIS (http://www.qgis.org/api/classQgsOverlayAnalyzer.html#details) ...
2
votes
1answer
89 views
Intersection of convex polygons on a spherical surface
There are a number of algorithms available for the intersection of two convex polygons, but I am interested in an algorithm to find the intersection of two convex polygons on the surface of a sphere, ...
2
votes
2answers
209 views
How to single out country data from a world data map?
Say that i have two "data sources";
A global map of average wind speeds,
A shape file (or similar information) of all country borders in the world.
How do i combine these two sources and extract ...
2
votes
2answers
474 views
Is there a way to get at C's OGRLayer.Intersection() or OGRLayer.Clip() in Python?
I am working with OGR in Python and noticed that the C libraries have useful Intersection() and Clip() functions as part of the Layer class. Is there any way to get at these functions in Python? I ...
2
votes
1answer
310 views
Batch intersect from a text file using Python (ArcGIS)
I am attempting to modify my code below which reads from a text file of shapefiles and executes an intersect and outputs them to a user specified location:
import arcpy, sys, os
from arcpy import env
...
1
vote
0answers
101 views
Copied points not intersecting the original points
I'm using an arcpy search cursor to access a Oracle database. I have a simple Python class that I copy the returned row objects into, which gives me more flexiblity than the cursor.
The problem is ...
4
votes
1answer
280 views
automating forest cover calculations with Python
I have a layer of forest cover comprising ~ 30,000 individual forest patches, and I need to calculate the amount of forest cover within a 5 km buffer of each patch. The buffers all overlap each other, ...
8
votes
4answers
1k views
Best way to find the polygons crossed by a line
I'm trying to find all the polygons crossed by a single line (a GPS track).
I'm using the OGR library (from python) for computing this, but it's currently a bit 'brute-force' (and slow). For every ...
